fix: support array content blocks from AstrBot (multi-modal message format)

main.py

@@ -8,7 +8,7 @@ import re
 import time
 import uuid
 from pathlib import Path
-from typing import Optional
+from typing import Optional, Union
 
 LOG_FORMAT = "%(asctime)s [%(levelname)s] %(name)s: %(message)s"
 LOG_BUFFER_SIZE = 500
@@ -75,9 +75,14 @@ manager = AccountManager(
 )
 
 
+class ContentBlock(BaseModel):
+    type: str = "text"
+    text: str = ""
+
+
 class Message(BaseModel):
     role: str
-    content: str
+    content: Union[str, list[ContentBlock]]
 
 
 class ChatCompletionRequest(BaseModel):
@@ -89,6 +94,14 @@ class ChatCompletionRequest(BaseModel):
     tools: Optional[list[dict]] = None
 
 
+def _get_message_text(msg: Message) -> str:
+    """Extract plain text from a message, handling both string and array content."""
+    c = msg.content
+    if isinstance(c, str):
+        return c
+    return "".join(b.text for b in c if b.text and b.type == "text")
+
+
 def verify_api_key(authorization: Optional[str] = Header(None)) -> str:
     if not authorization:
         raise HTTPException(status_code=401, detail="Missing API key")
@@ -225,7 +238,7 @@ async def chat_completions(
     if not request.messages:
         raise HTTPException(status_code=400, detail="No messages provided")
 
-    prompt = request.messages[-1].content
+    prompt = _get_message_text(request.messages[-1])
     
     if request.tools:
         tool_desc = json.dumps(request.tools, ensure_ascii=False)
@@ -505,7 +518,7 @@ async def admin_chat(request: Request, admin_key: str = Header(...)):
     if not req.messages:
         raise HTTPException(status_code=400, detail="No messages provided")
 
-    prompt = req.messages[-1].content
+    prompt = _get_message_text(req.messages[-1])
     
     if req.tools:
         tool_desc = json.dumps(req.tools, ensure_ascii=False)